Pattern present on hominoidmolars in which there are five cusps separated by a Y-shaped fissure. This pattern is present on the molars of Aegyptopithecus and later hominoids including fossilhumans; modern humans more commonly have a T-pattern based on four cusps. It is believed that the Y-5 pattern is primitive for catarrhines and that the cercopithecoid bilophodont condition derived from it. In the late 1980s some workers questioned whether the Y-5 pattern was actually present on most hominoidspecimens. Also referred to as the dryopithecine pattern because these were the most ancient fossilhominoids when this pattern was first described.